Taxon pages to indicate GBIF taxonomy

[esko-piirainen]

Can be done only after main parts of this epic are implemented

IMPLEMENTATION NOTE:
dw response has
taxon.id (full URL) - for example http://tun.fi/MX.1 or http://gbif.org/species/1
taxon.qname - for example MX.1 or gbif:1

taxon.qname is a new field; current implementation uses taxon.id.
Might be cleaner to use the new taxon.qname field.